POLYMERIZATION OF AN ACETOXYVINYL SUBSTITUTED CHLOROCYCLOPHOSPHAZENE

The vinyl acetate derivative, (alpha-acetoxyvinyl)tetrachlorocyclotrip hosphazene (1), has been used in radical homopolymerization and copoly merization reactions with methyl methacrylate, (MMA) and styrene. The 1,1-disubstituted olefin did not undergo radical homopolymerization. C opolymers derived from MMA and 1 contained only low amounts (<2 mol%) of 1. A maximum incorporation of 20 mol% of phosphazene monomer was ac hieved with styrene as comonomer. The data obtained in low-and high-co nversion copolymerizations with styrene were used to calculate the mon omer reactivity ratios. The results of the calculations show that the terminal model is not operative. Calculation for the penultimate model with r(2) = 0 resulted in r(1) and r(1)' values of 2.8 +/- 0.2 and 0. 7 +/- 0.1, respectively. For the hypothetical homopolymer of 1 a T-g v alue of 441 K was calculated. All the copolymers with styrene exhibit flame-retardant properties.